I'm seeing 50-60% appreciation over the last 4-5 years of holding plus significant pay down of mortgage plus some residual cash flow. 

It is a high volume play to get residual income...

The plan is to create enough residual income (rentals both single and multi-family) to replace half of my income and give longer-term retirement money with the other half coming from flipping houses (a few a year).  

However, as a developer, doing a residual analysis is a much more pertinent measure of value.A residual analysis involves establishing the value of the highest and best use of the land and deducting all project cost together with a target development profit and commissions and closing costs from the total value,The “residual” number represents the amount that can be assigned to land value under the project planned to be built on it.Let me know if you are interested in using this method and I’ll send you a short pro forma that runs this analysis.

Housing just got a residual effect as it’s where people try to store wealth in times good or bad.

Loose lay, interlocking, self adhesive, glue down?

So the listing are rental markets only(low budget residual income properties) then - to anyone wondering - don't go there trying to do a fix and flip for profit. :-)Kudos,Mary

@Johnny Nguyen Heat treatment will kill any that are present but there is no residual effect.

This could give you a little safety net if something were to arise where you needed money, you could tap into those funds designated for mortgage acceleration.Obviously, you could be more/less aggressive/conservative with the residual income you set aside based on your goals and cashflow ie $500/month or $5,000 every 10th month.As for opportunity costs and putting that money into other cashflowing assets, it is still better to pay down debt in your main home rather than having the funds sitting in an account not working for you correct?  

It means it requires a decent amount of working capital / investment upfront while the first deals are made, but after a few years should pay out nicely as the on ground partner builds up enough residual cash flow from their profit share of all the deals they've done so far.I'm not for a moment advocating that people go out and do this by themselves remotely, rather that instead of paying a service provider a big fee upfront and then being left to try to make profit in the long term, remote partners are better served by finding appropriate on ground partners whose incentives are aligned to their own.